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    <script>
        // 打印五行五列星星
        var str = '';
        for (var i = 1; i <= 5; i++) { // 外层循环负责打印五行
            for (var j = 1; j <= 5; j++) { // 里层循环负责一行打印五个星星
                str = str + '★';
            }
            // 如果一行打印完毕5个星星就要另起一行 加 \n
            str = str + '\n';
        }
        console.log(str);
    </script>
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